Q39548 (KSB_CUCMA) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names	Recommended name: Ent-kaur-16-ene synthase, chloroplastic EC=4.2.3.19 Alternative name(s): Ent-kaurene synthase Ent-kaurene synthase B Short name=KSB
Organism	Cucurbita maxima (Pumpkin) (Winter squash)
Taxonomic identifier	3661 [NCBI]
Taxonomic lineage	cellular organisms › Eukaryota › Viridiplantae › Streptophyta › Streptophytina › Embryophyta › Tracheophyta › Euphyllophyta › Spermatophyta › Magnoliophyta › eudicotyledons › core eudicotyledons › rosids › fabids › Cucurbitales › Cucurbitaceae › Cucurbiteae › Cucurbita

Protein attributes

Sequence length	789 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Catalyzes the conversion of ent-copalyl diphosphate to the gibberellin precursor ent-kaur-16-ene.
Catalytic activity	Ent-copalyl diphosphate = ent-kaurene + diphosphate.
Cofactor	Binds 3 magnesium ions per subunit By similarity.
Pathway	Plant hormone biosynthesis; gibberellin biosynthesis.
Subcellular location	Plastid › chloroplast.
Tissue specificity	Abundant in most tissues. Present in low amounts in mature cotyledons.
Domain	The Asp-Asp-Xaa-Xaa-Asp/Glu (DDXXD/E) motif is important for the catalytic activity, presumably through binding to Mg2+.
Post-translational modification	The N-terminus is blocked.
Sequence similarities	Belongs to the terpene synthase family.
Biophysicochemical properties	Kinetic parameters: KM=0.35 µM for copalyl diphosphate pH dependence: Optimum pH is 6.8-7.5.

Ontologies

Keywords
Cellular component	Chloroplast Plastid
Domain	Transit peptide
Ligand	Magnesium Metal-binding
Molecular function	Lyase
Technical term	Direct protein sequencing
Gene Ontology (GO)
Biological_process	gibberellin biosynthetic process Inferred from electronic annotation. Source: UniProtKB-UniPathway
Cellular_component	chloroplast Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular_function	ent-kaurene synthase activity Inferred from electronic annotation. Source: EC magnesium ion binding Inferred from electronic annotation. Source: InterPro
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Transit peptide	1 – ?		Chloroplast Potential
	Chain	? – 789		Ent-kaur-16-ene synthase, chloroplastic		PRO_0000033626
Regions
	Motif	536 – 540	5	DDXXD motif
Sites
	Metal binding	536	1	Magnesium 1 By similarity
	Metal binding	536	1	Magnesium 2 By similarity
	Metal binding	540	1	Magnesium 1 By similarity
	Metal binding	540	1	Magnesium 2 By similarity
	Metal binding	680	1	Magnesium 3 By similarity
	Metal binding	684	1	Magnesium 3 By similarity
	Metal binding	688	1	Magnesium 3 By similarity

Sequences

	Sequence		Length	Mass (Da)
	Q39548 [UniParc]. Last modified November 1, 1996. Version 1. Checksum: 8CC87F2884CCD7F2	FASTA	789	89,362
	10 20 30 40 50 60 MYLSRPTGVA RFAASSSSSS SASLFPGVDV DTTTKTGALH FEETKERIKK LFDKVELSVS 70 80 90 100 110 120 AYDTAWVAMV PSPNSLNQPL FPECINWVLD SQHADGSWGL LHNDQLLMKA NLLSTLACVL 130 140 150 160 170 180 TLKRWNIGHD HMSKALDFIK SNIASATDEN QRSPVGFDII FPGMIEYAKD LNLNLPLAPT 190 200 210 220 230 240 NVDALVRKKE LELRSCRSNS EGGKAYLAYV SEGIGKLQDW DMVMQYQRKN GSLFNSPSTT 250 260 270 280 290 300 AAAFMHRNDD GCFDYLRSLL QKFDGSVPTI YPLDIYARLH MVDSLQKFGI ARHFKEEIRS 310 320 330 340 350 360 VLDETYRCWM QGEENIFLDA STCAMAFRML RVEGYDVSSD QLTQFSEDIF PNCLGGYLKD 370 380 390 400 410 420 FGASLELYKA SQIITHPDES VLENINSWTS RFLKHGLSSD SVWSDRTDSV VKQEAVNALE 430 440 450 460 470 480 FPYNATLERL ISKRAMESYS GDIVRISKSP YACLNFGHQD FLELAVEDFN TLQRIHLKEL 490 500 510 520 530 540 EELQRWVVEN KLDELKFFRL HLGYCYFAAA ATLTDPELHD ARIAWAQNGV LTTVVDDFYD 550 560 570 580 590 600 GGGSEEELDN LIELVEKWDP DGEVGYCSKD VEIVFLALHS TVCEIGRRAL VWQGRSVMRN 610 620 630 640 650 660 VIDGWLALLK VMRKEAEWST NKVVPSMGEY MEQAHVSFAL GPIILPMLFF VGPKLSEEMI 670 680 690 700 710 720 GSCEYQKLYK LMSTAGRLKN DIRSYDRECK EGKLNILSLW MIDGGGNVTK EEAIEAIKGD 730 740 750 760 770 780 FERAIRELLG LVLQENTTIP RACKDLFWKL MSIVNLFYME DDGYTSNRLM NTVKAMFEQP MDLDALLNK

References

[1]

"Molecular cloning and characterization of a cDNA encoding the gibberellin biosynthetic enzyme ent-kaurene synthase B from pumpkin (Cucurbita maxima L.)." Yamaguchi S., Saito T., Abe H., Yamane H., Murofushi N., Kamiya Y. Plant J. 10:203-213(1996) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Strain: cv. Riesenmelone gelb vernetzt. Tissue: Immature seed.

[2]

"Purification and properties of ent-kaurene synthase B from immature seeds of pumpkin." Saito T., Abe H., Yamane H., Sakurai A., Murofushi N., Takio K., Takahashi N., Kamiya Y. Plant Physiol. 109:1239-1245(1995) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE OF 217-229; 370-389; 395-403; 434-448 AND 615-622, CHARACTERIZATION. Strain: cv. Riesenmelone gelb vernetzt. Tissue: Endosperm.

Cross-references

Sequence databases
EMBL GenBank DDBJ	U43904 mRNA. Translation: AAB39482.1.
PIR	T09672.
3D structure databases
ProteinModelPortal	Q39548.
ModBase	Search...
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Enzyme and pathway databases
UniPathway	UPA00390.
Family and domain databases
Gene3D	1.10.600.10. 1 hit. 1.50.30.10. 1 hit.
InterPro	IPR001906. Terpene_synth_N. IPR005630. Terpene_synthase_metal-bd. IPR008930. Terpenoid_cyclase/PrenylTrfase. IPR008949. Terpenoid_synth. [Graphical view]
Pfam	PF01397. Terpene_synth. 1 hit. PF03936. Terpene_synth_C. 1 hit. [Graphical view]
SUPFAM	SSF48239. Terp_cyc_toroid. 2 hits. SSF48576. Terpenoid_synth. 1 hit.
ProtoNet	Search...

Entry information

Entry name

KSB_CUCMA

Accession

Primary (citable) accession number: Q39548

Entry history

Integrated into UniProtKB/Swiss-Prot:	April 26, 2005
Last sequence update:	November 1, 1996
Last modified:	May 1, 2013
This is version 68 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Plant Protein Annotation Program